said they did not think lesson observations were the most effective way of assessing staff performance.
Andrew Harden, the union's head of FE, said the majority of teachers found that observations led to "increased stress levels". He added: "Our members believe that the current system of lesson observations is not fit for purpose and that a complete overhaul is required."
The prospect of no-notice inspections, first proposed by Sir Michael in 2012, has also re-emerged after the "Trojan Horse" investigation into schools in Birmingham, with the chief inspector arguing in June that they would be the "best way to make sure.inspectors see schools as they normally are". This proposal would be included in the consultation, Ms Fitzjohn said.
But the concept has proved a tricky one for the FE sector to adapt to, because of the range of provision in larger colleges and the high proportion of students likely to be based in a workplace at any one time.
Although no-notice inspections are already used occasionally in the sector, Ms Fitzjohn said the watchdog "could use more of them". But she added that there would be "clear disadvantages" to a blanket introduction, not least the difficulties of meeting work-based learners and local employers at short notice.
"These are meaningful conversations because they are so important to the process," she added. "There are opportunities to use [no-notice inspections] more, but not to use them all the time."
This view was supported by Ms Mercer, who warned that no-notice inspections would inevitably exclude huge swathes of colleges' provision.
"Will this actually be a report worth reading?" she said. "Do they want to catch people out or find out what's working? We can already have no-notice inspections for safeguarding issues. That should be how it should stay."
`No-notice for all is unrealistic'
In 2012, Exeter College was one of two FE providers to be given a no-notice inspection under an Ofsted pilot scheme. Principal Richard Atkins says that the experience was positive for the college, which was rated outstanding. Staff "much preferred" the shorter notice period and found it less stressful.
"There were some real positives and our staff loved it, but to apply this to all inspections is unrealistic," he says. "I think a day or two notice would help to ensure that the principal - whose job may or may not be on the line - is able to attend. It would be a big logistical exercise to get the inspection started on a Monday morning without any notice."
Mr Atkins, who is also president of the Association of Colleges, is concerned about the prospect of grades being removed from lesson observations. "I don't see grading lesson observations as entirely negative," he says. "It's a way to identify staff training needs and spread good practice.
"What makes me nervous about Ofsted getting rid of grades is that it would make it much more difficult for a college to challenge any judgements. Even if inspectors just give feedback, teachers will try and work out what grade they would have got."